package Java集合;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

public class test {

    public static void main(String[] args) {
        ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
        map.put("key1", "value1");
        map.put("key2", "value2");
        map.put("key3", "value3");
        System.out.println(map.get("key1"));
    }
}
